If the projections of climate change prove to be true and sea levels rise, there will be harrowing implications for much of human life on the shores. A new study released last week emphasizes the severity of this impact on culture: a whole fifth of the 720 listed UNESCO World Heritage Sites could be lost.

The study — “Loss of cultural world heritage and currently inhabited places to sea-level rise” by Ben Marzeion of the Institute for Meteorology and Geophysics at the University of Innsbruck and Anders Levermann of the Potsdam Institute for Climate Impact Research and Institute of Physics at Potsdam University — appears in Environmental Research Letters, an online journal published by IOP Science. As the researchers state:

If the current global mean temperature was sustained for the next two millennia, about 6% (40 sites) of the UNESCO sites will be affected, and 0.7% of global land area will be below mean sea level. These numbers increase to 19% (136 sites) and 1.1% for a warming of 3 K. At this warming level, 3–12 countries will experience a loss of more than half of their current land surface, 25–36 countries lose at least 10% of their territory, and 7% of the global population currently lives in regions that will be below local sea level. Given the millennial scale lifetime of carbon dioxide in the atmosphere, our results indicate that fundamental decisions with regard to mankind’s cultural heritage are required.

If the waves ride up to your home and life as you know it is changed forever, perhaps the survival of the old church nearby might not be at the top of your mind. However, while sea levels aren’t likely to rise at such cinematically apocalyptic levels, perhaps the gradual deterioration of cultural sites might ring some alarm bells. Marzeion himself isn’t quite so hopeful, telling the Guardian: “I’m not overly optimistic that culture means more interest in the subject. It’s hard to convince people it’s a problem if they’re not convinced.”

Human history has congregated along the oceans, and thus many of the oldest remains of civilization are in the biggest danger. You can view the litany of the 136 sites that would be potentially impacted by a rise in waters over the next 2,000 years, including the Sydney Opera House, the Bruges historic center, forts and castles in Ghana, the city of Venice, the Hiroshima Peace Memorial, the island of Mozambique, and the Statue of Liberty. And many of those sites aren’t just facing danger hundreds of years from now, but in the current century.

The study is fairly narrow, only taking in this one aspect of climate change, which could also change temperature and air conditions that could cause catastrophic material decay. UNESCO itself has been proactive in climate change initiatives, hosting a Synthesis Science-Policy Workshop on Climate Change Impacts in Major Mountainous Regions of the World this January in Paris that followed similar workshops in 2013 in Nepal, Costa Rica, and Kenya. Back at their 29th session in 2005, the issues were a central focus and resulted in a decision that noted “the impacts of climate change” are already effecting many sites and will likely impact “many more World Heritage properties, both natural and cultural in the years to come.” Whether or not they can serve as a sort of canary in the mine for climate change will be up to public initiative.